NASA’s Mars 2020 Rover Update: SuperCam Will Detect Organic Materials

When NASA’s next landing mission to the red planet — Mars 2020 Rover — launches in its eponymous year, it will have onboard a new imaging device that is a major improvement to the ChemCam currently deployed on the Curiosity rover. Called SuperCam, it will feature a number of upgrades that will give the rover new spectral and imaging abilities.

According to NASA, SuperCam will examine “rocks and soils with a camera, laser and spectrometers to seek organic compounds that could be related to past life on Mars. It can identify the chemical and mineral makeup of targets as small as a pencil point from a distance of more than 20 feet (7 meters).”

To do that, SuperCam will use a faster version of the Laser Induced Breakdown Spectroscopy (LIBS) system that ChemCam already uses. LIBS works by firing a burst of laser, lasting only a few billionths of a second, at its target object and vaporizing it. The excited atoms in the vapor carry telltale signatures of their chemical origins, which can be captured and identified by using spectroscopy. Along with LIBS, SuperCam will also have “the non-destructive analysis ability of Raman spectroscopy, capable of detecting carbon-based signatures of organic materials,” according to a statement released Monday by the Optical Society (OSA).

Raman spectroscopy uses lasers of two different colors to excite molecules and then analyzes the energy caused by the vibrations of the molecules to identify the chemicals, making the method non-destructive.

The ChemCam uses a Nd:KGW (neodymium-doped potassium gadolinium tungstate) crystal as a lasing medium, while the upgraded LIBS in SuperCam will use a Nd:YAG (neodymium-doped yttrium aluminum garnet) crystal. That allows SuperCam to function over a broader range of temperatures.

Producing two lasers and giving SuperCam the ability to switch between two different lasing and operational modes was a technical challenge since the device will need to maintain a stable temperature to function, despite a large variation in external temperatures. The rocky terrain of Mars also posed difficulties for stability, as did the need to ensure keeping the spectroscope free of contamination. And then, there are the size and weight constraints that affect every device that hopes to make it into space.

The chemical probe is being built and tested in France by Thales Group, the Centre National d’Etudes Spatiales and the Research Institute in Astrophysics and Planetology. Results from the tests of a fully representative model of the SuperCam will be presented during the OSA Laser Congress to be held from Oct. 1-5 in Nagoya, Japan. The tests included not just the functioning of the imaging and spectroscopy systems of SuperCam but also its durability in harsh Martian environment.

Other than SuperCam, Mars 2020 Rover will also feature a number of cameras to assist in and record the descent and landing of the rover. There are also two sets of NavCams for assisting in navigation, and six HazCams to evaluate potential hazards in the rover’s path. The CacheCam takes pictures from the top “of sampled materials and the sample tubes as they are being prepared for sealing and caching,” according to the NASA website. The other science cameras include Mastcam-Z (like its predecessor on Curiosity, it provides a 3D view), Pixl (uses X-ray fluorescence to identify chemical elements), Sherloc (which can take extreme close-up images of the target area) and Watson (supports Sherloc with larger context images of the target area).